Can you think of any movies/tv shows/anime that depict a protagonist struggling with amnesia-like symptoms after being involved in time travel?
I am struggling a bit to word the question so I'll explain my thought process a bit.
I was thinking about Back to the Future style time travel where someone goes back in time, makes alterations to the past, and returns to a different life around the time they left but without actually acquiring the memories of their new life. Most of the time this happens at the end of the movie or series and they're depicted only slightly confused but the viewer is given the impression they'll integrate just fine. I'm wondering what's out there for media where the conclusion of the protagonist's adventures with time travel is just the beginning and the protagonist now has to struggle to make sense of everything.
Even with the short time loop/do-over premise that's in movies like Palm Springs, Groundhog Day, and Omni Loop I feel like it could be difficult to interact with people afterwards. I imagine knowing everything about someone and having them regard you as a stranger would be frustrating and overwhelming.
From what I've seen the premise seems a bit under explored.
Stargate SG-1, Season 4, Episode 6 has a variant of the loop trope, but everyone (including most of the protagonists, and everyone else on earth) don't remember what happens, while two protagonists remember every loop until they are able to stop the looping.
They debrief the others who don't remember at the end (except for the things they did when they took a loop off anyway!) - but they didn't miss too much since everyone else on earth missed it.
Another fictional work - a book, not a movie / TV show / anime - is Stephen Fry's 1996 novel Making History. The time travel aspect is questionable - he sends things back in time to stop Hitler being born, but no people travel through time. However, he remembers the past before his change, and has to deal with the consequences of having the wrong memories relative to everyone else.
Weirdly, season 4 of both Fringe and Eureka have a portion of the main cast shunted into an altered timeline and having to reconcile their original memories with their "new" histories, to varying degrees of success.
Travelers kinda inverts the premise in its second season, where a bunch of time travellers sent back to fix the past start seeing their superior foreknowledge slowly rendered useless by the fact that their mission is actually succeeding in changing the future.
They did a good job with the gradual changes, but I couldn't watch it all the way through. The main cast is just too irritating to watch. If I wanted to watch (the equivalent of) children deal with an interesting premise in adult bodies, I would just go back to Big or 13 Going On 30.
It's one of my favorite anime, but the characters can be really annoying sometimes. Still, I found it to be less annoying later on, as the stakes got raised and things start to go to shit
12 Monkeys with Bruce Willis. Not exactly amnesia but extreme confusion and lack of emotional control. Some of that was due to time travel and some due to the extreme emotional trauma his character experienced.
Could be a partial spoiler but Date a Live has it involved in the general story. If I state how it'll work it would be a major spoiler, so not detailing it further.
Not exactly the same premise that you described, but just a first reaction on the title is try Final Fantasy X. It’s certainly got time travel elements as well as amnesia!
So the premise is: they travel back in time, change their future, travel back to the present, forget everything they did while time traveling, and now have to just experience their new future without knowing anything changed? Do I have a that right?
I mean, how do you know this isn't the backstory for every character in every story ever? How do you know you didn't JUST do this yourself?
Ahh, yeah, I think I didn't quite follow OP's request. The part they don't remember is the time between where they traveled to in the past and their "present", and the story is about them intuiting what happened in there.
From the title it sounded like the protagonist was suffering amnesia-like symptoms about how the world used to be along with everyone else.